[scnlib] Fix include CMAKE_INSTALL_INCLUDEDIR

[WangWeiLin-MV]

Fixes include CMAKE_INSTALL_INCLUDEDIR since target scn::scn lost INTERFACE_INCLUDE_DIRECTORIES,

Fixed by backporting upstream patches in eliaskosunen/scnlib#111.

Format and unify EOL to LF of portfile.cmake.

Checklist

• Changes comply with the maintainer guide.
• SHA512s are updated for each updated download.
• The "supports" clause reflects platforms that may be fixed by this new version.
• Any fixed CI baseline entries are removed from that file.
• Any patches that are no longer applied are deleted from the port's directory.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is added to each modified port's versions file.

Test

The port usage tests pass with the following triplets:

• x64-linux
• x64-windows